• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.703-719
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• 1995

The purpose of this study was to observe the effects of the periodontal ligament on the healing and the formation of alveolar bone in the extraction socket, when this ligament had artificially remained in the socket during the tooth removal. Twenty rats aged 4 weeks were used and devided into the control groups (10) and the experimental groups (10) in this study. The maxillary right and left first molars were extracted in both groups. In the experimental groups the periodontal ligament was remained in the extraction sockets using 0.4% ${\beta}-aminopropionitrile$, and in the control the periodontal ligament was completely removed by curettage. At 1, 3, 5, 7 and 14 days after the tooth extraction, rats in both groups were serially sacrificed. And the specimens were prepared with Hematoxylin-Eosin stain for the light microscopic evaluation. The results of this study were as follows ; 1. On 1 day, the periodontal ligament was only found in the extraction socket walls of the experimental groups, and there was not the distinguishable difference between the control and the experimental groups. 2. On 3 days, there were more collagen fibers and the appearance of higher cellular density in the experimental groups than in the control. And the cells and collagen of the periodontal ligament were so actively proliferated and synthesized that invaded into the connective tissue of the extraction sockets in the experimental groups. 3. In the experimental groups, the trabecular bone was formed on the basal and lateral bone surface on 5 days. However, there was not the new bone forming appearance in the control groups at this time. 4. On 7 days, the trabecular bone was formed in the control groups. 5. On 14 days, the extraction sockets were almost entirely filled with the bony trabeculae in both groups. But, compared to the control group, the experimental groups showed the prominent differences in the amount & the density of the new bone formed. In conclusion, it was suggested that the residual periodontal ligament tissue in the extraction socket will play a major role as the important cell source in the healing and the new bone formation of the extraction socket.

• Journal of Veterinary Clinics
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• v.29 no.2
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• pp.148-153
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• 2012

Atrial natriuretic peptide (ANP) is associated with the variety of disorders of myocardial function. The effect, however, of myocardial infarction (MI) on ANP has not been fully described. Thus, this study investigated the effect of experimental MI, induced by left coronary artery ligation, on ANP secretion. Male Sprague-Dawley rats aged 60 d underwent ligation of the left anterior descending coronary artery to induce MI and were compared with a group that underwent a sham operation. Rats of sham operation had a similar procedure without having the suture tightened around the coronary artery. Animals were sacrificed at 1, 3, 6, 12, and 18 h or 1, 3, 5, 7, 14, and 30 d after the procedure. MI size was assessed by planimetry and perimetry, and plasma ANP levels were determined by radioimmunoassay. Mean infarct size was 39.6-44.5% of the left ventricle after coronary occlusion in experimental groups. No significant differences were observed in infarct size among groups. In contrast, the concentration of plasma ANP was significantly higher at 1, 3, 6, 12, 18, and 24 h after left coronary artery ligation than in sham animals. This parameter, however, did not differ significantly at 3, 5, 7, 14, and 30 d after ligation compared with sham-ligated controls. These results demonstrate that plasma ANP levels are markedly increased in the early phase of MI in the male rat and can be a useful biomarker for diagnosis in acute MI.

• Journal of Food Hygiene and Safety
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• v.6 no.1
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• pp.1-12
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• 1991

Fischer 344 rats aged six weeks were diYided into four groups and group 1, 2, and 3 of rats were given an intraperitoneal injection of diethylnitrosamine at 200 mg/kg body weight and group 4 was given saline alone. Two weeks after beginning of the experiment, group 1 and 2 of rats were begun to feed on diets containing 0.02% 2-acetylaminofluorene as a promoter for four weeks. Three weeks after beginning of the experiment, all groups were performed partial hepatectomy. During the last two weeks, group 1 and 3 of rats were received subcutaneously 3 consecutive weekly doses of iron dextran at 0.125 ml/100 g body weight. Subcutaneous injection of iron dextran resulted in hepatic siderosis in group 1 and 3 of rats. Pre neoplastic nodules were identified histopathologically by two markers, resistance to exogenous iron accumulation and glutathione S-transeferase placental form (GST-P) activity, while early carcinogen induced foci were hardly resistant to iron accumulation and though a few lesions were identified, it could hardly be distincted from normal hepatocytes of surroundings. However, GST-P positive nodules as well as foci were clearly distincted from normal hepatic cells of surroundings. In the quantitative analysis of carcinogen-induced nodules and foci, more lesions were detected by immunohistochemical method for GST-P than by prussian blue staining for resistant to iron accumulation. It is concluded that immunohistochemical marker for GST-P is more sensitive and reliable than iron-resistance marker, and that iron-resistance is not useful marker for early detection of carcinogen-induced hepatic lesions.

• Journal of the Korean housing association
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• v.25 no.6
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• pp.11-18
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• 2014

This study is to explore the housing problems and environment conditions perceived by residents in traditional houses in Suzhou, China. The empirical data is based on a questionnaire survey, which were from 100 residents in traditional area in Gusu area of Suzhou. In order to understand the traditional houses, on-the-spot investigation and literature review methods are adapted in this study. The main findings are as follows. Firstly, most of residents are middle-aged or older people, and their income is not high. Secondly, there are almost no cases of organizing independent workroom and storage room in their housing. Moreover, the main problems are mildew, theft, rats and cockroaches, etc. Finally, the satisfaction with the internal housing environment was appeared reasonable, but the external environment is unsatisfactory. Therefore, the external environment should be more considered in the Chinese traditional housing policy.

• Biomedical Science Letters
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• v.15 no.2
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• pp.127-133
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• 2009

This study was designed to investigate the effects of high concentration of (-)-epigallocatechin-3-gallate(EGCG) on the neuronal activity of rat substantia nigra dopaminergic neurons. Sprague-Dawley rats aged 14 to 16 days were decapitated under ether anesthesia. After treatment with pronase and thermolysin, the dissociated dopaminergic neurons were transferred into a chamber on an inverted microscope. Spontaneous action potentials and potassium currents were recorded by standard patch-clamp techniques under current and voltage-clamp modes respectively. 18 dopaminergic neurons(80%) revealed inhibitory responses to 40 and 100 ${\mu}M$ of EGCG and 4 neurons(20%) did not respond to EGCG. The spike frequency and resting membrane potential of these cells were decreased by EGCG. The amplitude of afterhyperpolarization was increased by EGCG. Whole potassium currents of dopaminergic neurons were increased by EGCG(n=10). These experimental results suggest that high concentration EGCG decreases the neuronal activity of the dopaminergic neurons by altering the resting membrane potential and afterhyperpolarization.

• Biomedical Science Letters
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• v.16 no.1
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• pp.46-52
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• 2010

This study was designed to investigate the effects of sphingosine-1-phosphate on the neuronal activity of rat medial vestibular nuclear neurons. Sprague-Dawley rats aged 14 to 16 days were decapitated under ether anesthesia. After treatment with pronase and thermolysin, the dissociated medial vestibular nuclear neurons were transferred into a chamber on an inverted microscope. Spontaneous action potentials and potassium currents were recorded by standard patch-clamp techniques under current and voltage-clamp modes respectively. 15 medial vestibular nuclear neurons revealed excitatory responses to 1 and $5\;{\mu}M$ of sphingosine-1-phosphate. The spike frequency and resting membrane potential of these cells were increased by sphingosine-1-phosphate. The amplitude of afterhyperpolarization was decreased by sphingosine-1-phosphate. Whole potassium currents of medial vestibular nuclear neurons were decreased by sphingosine-1-phosphate (n=12). Sphingosine-1-phosphate did not affect the charybdotoxin-treated potassium currents. These experimental results suggest that sphingosine-1-phosphate increases the neuronal activity of the medial vestibular nuclear neurons by altering the resting membrane potential and afterhyperpolarization.

• The Journal of Korean Medicine
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• v.25 no.3
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• pp.90-98
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• 2004

Objectives : The present study was undertaken to investigate the molecular mechanisms of Ichungwhan for inhibition of cyclooxygenase-2 (COX-2) gene expression via suppression of NF-κB (nuclear factor κB) using aged rats. NF-κB is the most important modulator of inflammation and NF-κB regulates the gene expression of several pro-inflammatory cytokines, such as COX-2. Methods : In the experiment, we investigated the scavenging property of Ichungwhan on reactive species (RS) including nitrogen-derived species (RNS), measured by DCF-DA (2,7-dichlorodihydrofluorexcein diacetate) / DHR 123 (dihydrorhodamine 123) assay. Protein expression levels of COX-2, NF-κB, p-ERK and p-p38 were assayed by western blot. Results : We showed that Ichungwhan inhibits RS including RNS and inhibits NF-κB activation by blocking the dissociation of inhibitory IκB-β via suppression of IKK pathway. Also, Ichungwhan inhibits COX-2 gene expression. Conclusions : These findings suggest that Ichungwhan modulates COX-2 gene expression via suppression of the NF-κB pathway.

• Korean Journal of Veterinary Research
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• v.40 no.2
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• pp.361-371
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• 2000

It has been recently reported that 2-bromopropane (2-BP) induces male reproductive toxicity in both human and experimental animals. However, delayed effects of 2-BP on male reproductive system have not been investigated in detail. The present study was conducted to investigate the testicular toxicity of 2-BP and to determine the recovery of normal spermatogenesis in Sprague-Dawley rats. Male rats aged 5 weeks were administered 1,000mg/kg 2-BP by gavage daily for 4 weeks and sacrificed sequentially at 1, 2, 3, 4 and 12 weeks after initiation of 2-BP treatment. Testicular toxicity was evaluated qualitatively by histopathological examinations and quantitatively by reproductive organ weights, spermatid head count, and repopulation index. In the 2-BP treated rats, the body weights was significantly suppressed and the weights of testes and epididymides were also decreased in a time-dependent manner. On histopathological examination, spermatogonia in stages I-VI and preleptotene and leptotene spermatocytes in stages VII-IX were strongly depleted at 1 week of dosing. Spermatogonia were depleted extensively in all spermatogenic stages at 2 weeks. Continuing with the evolution of spermatogenic cycle, zygotene spermatocytes, pachytene spermatocytes, and round spermatids were sequentially depleted at 2, 3, and 4 weeks of dosing due to the depletion of their precursor cells. Vacuolization of Sertoli cells and spermatid retention were also observed at all time points, suggesting that 2-BP induced Sertoli cell dysfunction. At 12 weeks, after 8 weeks recovery, most of the tubules appeared severely atrophic and were lined by Sertoli cells only. Leydig cell hyperplasia in the interstitial tissue was also found. In addition, dramatic reductions in the number of spermatid heads and repopulation index were observed, indicating that 2-BP-induced testicular injury is irreversible. These results indicate that 4 weeks repeated-dose of 1,000mg/kg 2-BP results in a progressive germ cell loss due to the depletion of spermatogonia followed by long-term testicular atrophy in SD rats.

• Korean Journal of Pharmacognosy
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• v.38 no.3 s.150
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• pp.239-244
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• 2007

The herbal formulation (KH-204) mainly consisted of the fruits of Lycium chinense, Cornus officinalis, Rubus coreanus, Cuscuta chinensis and Schizandra chinensis. We investigated the effects of this herbal formulation on the penile erection and corpus cavernosum of spontaneous hypertensive male Rats (SHR). We used male SHR aged 16 weeks as a model of hypertension. The treatment groups received once a day oral doses KH-204 100 and 300 mg/kg per day for 4 weeks. Distilled water was administered in the control group. To investigate the penile erection, intracavernosal pressure (ICP) and mean arterial pressure (MAP) were recorded in all groups. We analyzed the distribution of NOS by immunohistochemical staining and the expression of nNOS, eNOS concentration in the isolated corpus cavernosum by western blotting. In the control group, ICP/MAP ratio was $14.9{\pm}1.4%$ after pelvic nerve stimulation. ICP/MAP ratio was markedly increased in the treatment group with KH-204 100, 300 mg/kg, compared with control group. Immunohistochemical staining for NOS showed that eNOS and nNOS was stained as brown color. Compared with the control group, NOS activities of KH-204 100, 300 mg/kg were increased significantly. Also the penile expression levels of nNOS, eNOS in KH-204 100, 300 mg/kg treatment group were more increased significantly than control group by western blotting. This study showed that KH-204 enhances the penile erection and the level of eNOS and nNOS expression of penile corpus cavernosum of male SHR.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.2
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• pp.153-160
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• 2017

Data are limited on biological mechanisms underlying the associations of sleep insufficiency with obesity and dyslipidemia. To explore these mechanisms, we investigated appetite-regulating hormones, stress-related hormones, and cardiometabolic indicators in association with sleep fragmentation, which is a type of sleep disorder. In an experimental study, we randomly allocated 40 Wistar male rats aged 7 weeks into four groups; rats with ad libitum sleep and ad libitum intake (Control), those exposed to sleep fragmentation (SF), those with diet restriction (DR), and those exposed to sleep fragmentation and diet restriction (SF+DR). Amongst them, 13-day chronic sleep fragmentation was applied to the SF and SF+DR groups while 50% reduction in chow intake was applied to the DR and SF+DR groups for 13 days. After these experiments, blood lipid and lipoprotein profiles, leptin, ghrelin, adiponectin, cortisol, epinephrine, and norepinephrine levels were compared among the four groups. In the results, the SF group showed the highest levels of serum ghrelin (P<0.001) and the lowest levels of serum adiponectin (P<0.01). All experimental groups showed higher levels of low density lipoprotein-cholesterol (LDL-C) than the Control (P<0.001). LDL-C levels and the ratio of LDL-C and high density lipoprotein-cholesterol were positively correlated with ghrelin levels (P<0.05) in the SF group, but not in the DR and SF+DR groups. In the SF group, the highest levels of serum free fatty acids were also observed and correlated with lower levels of serum adiponectin, which reflects insulin resistance (P<0.05). Based on these findings, we suggest that chronic sleep fragmentation may induce disturbances in lipid metabolism and appetite-regulating hormones independent of food intake, and these metabolic disturbances may be worse due to insulin resistance related to overeating, which is indicated by elevated ghrelin levels in sleep fragmentation. For persons with sleep insufficiency, anti-atherogenic dietary interventions may be recommended to prevent cardiovascular disease.